@book{SteinhausenKobelt2000,
  author    = {Steinhausen, Detlef and Kobelt, Helmut},
  title     = {Wirtschaftsstatistik f{\"u}r Studium und Praxis},
  edition   = {6., v{\"o}llig {\"u}berarb.},
  publisher = {Sch{\"a}ffer-Poeschel},
  address   = {Stuttgart},
  isbn      = {3-7910-1482-X},
  pages     = {XI, 389 S. : graph. Darst.},
  year      = {2000},
  language  = {de}
}
@book{Pooten2000,
  author    = {Pooten, Holger},
  title     = {Kennzahlen und Kennzahlensystem II: Statische Finanzanalyse},
  volume    = {10},
  edition   = {Lektion 5},
  publisher = {Euroforum},
  address   = {D{\"u}sseldorf},
  year      = {2000},
  language  = {de}
}